Principles of 3d Modeling with Andrew Klein

Critical Concepts :

Creating a Project-
Unlike programs like Photoshop where various images in a .PSD file are actually saved in that file, Maya references objects into the scene from exterior files. This means that if you don't take your image planes, textures, or sounds along with you IN THE SAME FILE HIERARCHY when you move your Maya file, Maya will not be able to locate your files. We do this by defining a project. We can make a set of folders in the explorer that we keep all of our work in. Then we can go to File-->Project-->Set and link our scene to our folder set up. We can also define our own in New, or modify the existing project in Edit Current.

Inserting Image Planes-
Image planes allow you to "trace in 3d". We can import an image into one of Maya's orthographic cameras to model off of by choosing View-->Image Plane-->Import Image. Once we find the file, we can then edit it's attributes to resize it and align it properly on the grid. I find it very helpful to create polygon planes as markers in physical space to help align multiple image planes. It is also best when working with multiple images planes to choose one view as a "Master" view for layout purposes. This meaning that when in doubt, align the model and to this view. For faces I usually choose the front view as the master. For Airplanes, the Top view just makes more sense. Once the image planes are in place, I can enter the attribute editor and make the visible in only the camera they are projected from, or I can move them off the center of the grid, or I can turn down the contrast with the Alpha Gain slider, etc....

Box Modeling-
The Idea behind box modeling is that we start with a cube, and simply extrude out parts from it, pulling it out like a block of clay, until we have out final shape. Making sure that the object is instanced, we can build just one half of the model in this way. Box Modeling uses all of the Techniques that we have previously talked about, but relies heavily on the extrude faces comand (which means you need to check your keep faces together option).

Specific to the concept of Box Modeling is the desire to maintain edge loops. As we extrude out new faces, edge loops are the continuing band of faces that wrap around a surface. We can split an edge loop in Maya 8.5 and above using Edit Mesh-->Insert Edge Loop which will in essence use the split polygon tool in a loop around the surface. In Maya 6.5 and below, we can use the MJPolyTools tool set to perform the same task. Here we see edge loops on an F22 model:

Very specific things happen when we are modeling with edge loops. At the junction of wherever we extrude out a chunk of faces, we will notice a 5-point star develop. Notice the 5-point star here on the wing:

The 5-point star denotes the exact point where the edge flow is changing. In the case of this aircraft, it is also denoting where the fuselage stops and the wing begins. This is an extremely important concept because it determines how each of the parts of our model are defined. On one side of the star we have a wing, on the other, the body of the aircraft. When animating characters, it is important to have properly placed 5-point stars as they will be maximum extent an section of your model (such as the arm) can flex. We will look at this more later. For now, we should understand that at the 4 corners of each group of extruded faces (in this case, the wing), we will have a 5-point star.

Here is an photo/map from downtown San Francisco on Market Street at the corner with the Apple Store, Virgin Records, and Old Navy. Notice how we see Market (the major 45 degree angle bisector) intersects with both Stockon, and Ellis to form 4th which heads south. This is very similar to the sort of edge flow we want to see on our wings.

Cleaning up Lamina Faces-
Sometimes when modeling you will extrude out a face, but might forget to move it off of that plane. As a result, you get a lamina face, which has no geometry area because it has length but no width and as we all know A=LxW. If we multiply by zero, no matter what we multiply by, we will get zero as a result. This can cause unsettling problems in your model, that will only really be noticed if you are in the face component mode. Lamina faces are circled below. One solution to remove these is to delete the face on either side of the lamina face, then re-extrude or re-append the hole.

New as of Maya 2009 is a new selection tool for selecting faces. One drawback of this function is it doesn't easily let you see your face centers (which helps you identify lamina faces). In Window-->Settings/Preferences-->Preferences, you can access the following options to restore this funtion:

The other solution is to run a Mesh-Cleanup.

You will need to check these 3 options to make it work effectively as they work as redundancy checks:
-Lamina Faces
-Non Manifold Geometry
-Faces with 0 geometry area

Lamina faces are faces which have their edges stuck together. Non-manifold geometry is made from faces which no longer maintain that hallow egg-shell structure. And faces with 0 Geometry area were explained above. Jus thit Apply or Cleanup and you should be good. Check your mesh in Face component mode to be sure.

	Corsair Top Image
	Corsair Side Image
	Corsair Front Image
	P-38 Top Image
	P-38 Side Image
	P-38 Front Image
	F-22 Top Image
	F-22 Side Image
	F-22 Front Image

Click on the images below for links to Video Tutorials. This series covers creating an airplane using a box modeling method in Maya, with the first couple videos discussing proper setup procedure for inserting image planes, and setting a project. All images and videos are copyright Andrew Klein.
	In part 1 of this 10 part series, Andrew Klein (www.andrewklein.net) covers cropping images and changing levels in Photoshop to create suitable image planes for Maya
	In part 2 of this 10 part series, Andrew Klein (www.andrewklein.net) looks at creating and setting a project in Maya.
	In part 3 of this 10 part series, Andrew Klein (www.andrewklein.net) examines importing and repositioning our first image plane, the top-down image.
	In part 4 of 10 of this series, Andrew Klein (www.andrewklein.net) looks at how to align the remaining 2 image planes so that they match the top-down "master" view. This is done through the use of polygon planes which act as rulers.
	In video 5 of 10 from Andrew Klein (www.andrewklein.net), we begin actually modeling our aircraft from the box modeling method. By starting out with a cube, setting the initial creation values and moving verticies to match the blueprints, the form is created. Then the model is split in half and a duplicate instance is made to keep the model symmetrical.
	In video 6 of 10, Andrew Klein (www.andrewklein.net) rounds out the otherwise very boxy plane, and creates the first extrusion for the wings. This video introduces the extrude function and the insert edge loop function.
	In part 7 of 10, Andrew Klein (www.andrewklein.net) covers extruding out the main wings and inserting edgeloops for more detail.
	In part 8 or 10, Andrew Klein (www.andrewklein.net) looks at extruding out the back wings, the tail fin and begins the cockpit.
	In part 9 of 10, Andrew Klein (www.andrewklein.net) finishes the airplane cockpit and creates the air intake on the lowerside. At this time, he introduces the append polygon tool.
;	In the final video of this series, Andrew Klein (www.andrewklein.net) introduces the combine function which unites the two halves of the model, as well as the snap to grid functionality allowing verticies to be stuck to the centerline. From there, the tutorial examines how to merge components, and finally how to create a ready-to-animate propellor.